1. Field of the Invention
The present invention relates to an inkjet printing apparatus which adjusts a conveyance amount of a print medium corresponding to a change in a landing position of an ink droplet generated by a change of a distance between a print head and the print medium.
2. Description of the Related Art
There is proposed an inkjet printing apparatus which performs conveying control of a print medium for performing printing of high image quality on the print medium. For example, in Japanese Patent Laid-Open No. 2008-260170, it is disclosed that a conveyance error of the print medium due to eccentricity of a conveying roller or a variation of a conveyance amount existing for each rotational angle of the conveying roller is corrected. Then the conveyance of the print medium is performed by the corrected conveyance. In the inkjet printing apparatus disclosed in Japanese Patent Laid-Open No. 2008-260170, a test pattern is printed on a print medium, and then is in advance scanned, thereby correcting the conveyance amount of the print medium.
However, there are some cases of adopting an inkjet printing apparatus in which as a distance between the print head and a support surface supporting the print medium changes, a landing position of an ink droplet changes following the change of the distance. In this case, there is a possibility that even if only the conveyance error of the print medium due to eccentricity of the conveying roller or the variation of the conveyance amount existing for each rotational angle of the conveying roller is corrected, it is insufficient for the adjustment of the conveyance amount. Therefore there occurs a possibility of being incapable of performing the printing with an appropriate conveyance amount. In a case where the conveyance is not performed appropriately, there is a possibility that a clearance occurs between images printed by the respective scans, and thereby a white stripe is generated in the image. In addition, when the images printed by the respective scans excessively largely overlap with each other, in some cases there is generated a black stripe in the image. Therefore there is a possibility that a quality of a print image is degraded.